Field of the Invention
The present invention relates to a radiation detection apparatus and a radiation imaging system.
Description of the Related Art
Radiation detection apparatuses are widely used for medical imaging diagnosis and non-destructive inspection. There is known a method of obtaining a plurality of radiation images of an object with radiation having different energy components by using such a radiation detection apparatus and obtaining an energy subtraction image with a specific object portion being separated or emphasized based on the differences between the obtained radiation images. Japanese Patent Laid-Open Nos. 5-208000, 2011-235, 2011-22132, 2001-249182, and 2000-298198 have proposed radiation detection apparatuses which record radiation images with radiation having two different energy components by one irradiation of an object with radiation (one shot method) by using two radiation imaging panels to obtain an energy subtraction image. Japanese Patent Laid-Open No. 5-208000 has disclosed that a copper plate is arranged as a member for absorbing low-energy components of radiation between two radiation imaging panels. Japanese Patent Laid-Open Nos. 2011-235 and 2011-22132 have disclosed that a metal plate is used as this member, which contains, as a main component, Al, Ti, Ag, Pb, Fe, Ni, Cu, Zn, La, Cs, Ba, Sn, Sb, Tb, Ce, or Sm and has a thickness of 50 μm to 450 μm. Japanese Patent Laid-Open Nos. 2001-249182 and 2000-298198 have disclosed the use of radiation imaging panels using materials having different radiation absorption characteristics.